public Entry<K, V> next() {
        entry = iterator.next();
        return new BiMapEntry(entry);
      }

      @Override
      public void remove() {
        if (entry == null) {
          throw new IllegalStateException("no calls to next() since the last call to remove()");
        }
        V value = entry.getValue();
        iterator.remove();
        removeFromInverseMap(value);
        entry = null;

      if (conflict != null) {
        broken = entry;
        // We're definitely going to throw, but we'll try to keep the BiMap in an internally
        // consistent state by removing the bad entry.
        itr.remove();
      }
    }
    if (broken != null) {
      throw new IllegalArgumentException("value already present: " + broken.getValue());
    }
  }

  @Override